compiler: v -autofree can now compile itself

vlib/builtin/array.v

@@ -212,6 +212,12 @@ fn (a array) slice2(start, _end int, end_max bool) array {
 	return a.slice(start, end)
 }
 
+// array.clone_static returns an independent copy of a given array
+// It should be used only in -autofree generated code.
+fn (a array) clone_static() array {
+	return a.clone()
+}
+
 // array.clone returns an independent copy of a given array
 pub fn (a &array) clone() array {
 	mut size := a.cap * a.element_size
@@ -304,7 +310,7 @@ pub fn (a array) reverse() array {
 
 // pub fn (a []int) free() {
 [unsafe_fn]
-pub fn (a array) free() {
+pub fn (a &array) free() {
 	// if a.is_slice {
 	// return
 	// }

vlib/builtin/js/array.v

@@ -98,11 +98,17 @@ pub fn (a array) reverse() array {
 	return a
 }
 
+// array.clone_static returns an independent copy of a given array
+// It should be used only in -autofree generated code.
+fn (a array) clone_static() array {
+       return a.clone()
+}
+
 pub fn (a array) clone() array {
 	return a
 }
 
-pub fn (a array) free() {
+pub fn (a &array) free() {
 }
 
 // "[ 'a', 'b', 'c' ]"

vlib/builtin/js/string.v

@@ -26,6 +26,11 @@ pub fn tos(s byteptr) string {
 	}	
 }	
 
+// string.clone_static returns an independent copy of a given array
+// It should be used only in -autofree generated code.
+fn (a string) clone_static() string {
+	return a.clone()
+}
 
 pub fn (a string) clone() string {
 	return a
@@ -241,18 +246,9 @@ pub fn (c byte) is_letter() bool {
 	return (c >= `a` && c <= `z`) || (c >= `A` && c <= `Z`)
 }
 
-pub fn (s string) free() {
+pub fn (s &string) free() {
 }
 
-/*
-fn (arr []string) free() {
-	for s in arr {
-		s.free()
-	}
-	C.free(arr.data)
-}
-*/
-
 // all_before('23:34:45.234', '.') == '23:34:45'
 pub fn (s string) all_before(dot string) string {
 	pos := s.index(dot)

vlib/builtin/map.v

@@ -413,7 +413,7 @@ pub fn (m &map) keys() []string {
 }
 
 [unsafe_fn]
-pub fn (m map) free() {
+pub fn (m &map) free() {
 	free(m.metas)
 	for i := u32(0); i < m.key_values.size; i++ {
 		if m.key_values.keys[i].str == 0 {

vlib/builtin/string.v

@@ -104,6 +104,12 @@ pub fn tos3(s charptr) string {
 	}
 }
 
+// string.clone_static returns an independent copy of a given array
+// It should be used only in -autofree generated code.
+fn (a string) clone_static() string {
+	return a.clone()
+}
+
 pub fn (a string) clone() string {
 	mut b := string{
 		len: a.len
@@ -1141,7 +1147,7 @@ pub fn (u ustring) at(idx int) string {
 	return u.substr(idx, idx + 1)
 }
 
-fn (u ustring) free() {
+fn (u &ustring) free() {
 	u.runes.free()
 }
 
@@ -1165,19 +1171,10 @@ pub fn (c byte) is_letter() bool {
 	return (c >= `a` && c <= `z`) || (c >= `A` && c <= `Z`)
 }
 
-pub fn (s string) free() {
+pub fn (s &string) free() {
 	free(s.str)
 }
 
-/*
-fn (arr []string) free() {
-	for s in arr {
-		s.free()
-	}
-	C.free(arr.data)
-}
-*/
-
 // all_before('23:34:45.234', '.') == '23:34:45'
 pub fn (s string) all_before(dot string) string {
 	pos := s.index(dot) or {